Map - Thousand Islands (Indonesia) (Kabupaten Administrasi Kepulauan Seribu)

The Thousand Islands (Indonesian: Kepulauan Seribu) are a chain of islands to the north of Jakarta's coast. It forms the only regency of Jakarta, the capital of Indonesia. It consists of a string of 342 islands stretching 45 km north into the Java Sea at West Jakarta Bay and in fact north of Banten Province. Pramuka Island is the regency seat.

A decree states that 36 islands may be used for recreation. Of these, only 13 islands are fully developed: 11 islands are homes to resorts and two islands are historic parks. Twenty-three are privately owned and are not open to the public. The rest of the islands are either uninhabited or support a fishing village.

The modern history of the Thousand Islands begins with its role in the defenses of the city of Batavia for the Dutch East India Company (Vereenigde Oostindische Compagnie, abbreviated VOC) and the Dutch colonial empire. Before the arrival of the Dutch, these islands already had their present Malay language name. With the arrival of the Dutch, the islands received a second Dutch name. The Malay names are not forgotten, as both Malay and Dutch names of the islands are written side by side in some 18th-century Batavia maps. Since the establishment of Batavia in 1610, Pulau Kapal, later named by the Dutch as Onrust Island, has been a naval base.

After the VOC failed to obtain control of trade at Banten in 1610, the Dutch obtained permission from Prince Jayakarta to build a dock at one of the islands in Jakarta Bay as a place to repair and equip ships sailing to Asia, particularly South East Asia. The island Prince Jayakarta assigned to the VOC was Onrust Island, a 12 ha island 14 km from Jakarta.

In 1615 the VOC built a shipyard and a small storage house on the island, which Jan Pieterszoon Coen hoped would eventually develop into a trade and defence base against threats from Banten and England (1618). The VOC constructed a small rectangular fort with two bastions in 1656; the bastions protruded from the fort and were used as look-out posts. The Dutch enlarged the fort in 1671 and gave it an asymmetrical pentagonal shape with a bastion in each corner. The whole structure was made of red bricks and coral. In 1674 additional storage buildings were built.

In 1795, the position of the Dutch in Batavia became quite uncertain due to the war in Europe, and the situation became worse with the appearance in 1800 of a British naval squadron under the command of Captain Henry Lidgbird Ball of HMS Daedalus (1780). Daedalus, HMS Sybille, HMS Centurion (1774) and HMS Braave (1796) entered the area, which they referred to as Batavia Roads. They seized five Dutch armed vessels and destroyed 22 other vessels. Onrust island was under siege by the British and eventually destroyed.

After the British departed, the Dutch rebuilt the buildings and facilities, completing the work in 1806. However, a second British attack, led by Admiral Edward Pellew, again destroyed the fort. When the British occupied Batavia in 1810, they repaired the buildings in Onrust island until prior to their leaving Indonesia in 1816.

Onrust island again received attention in 1827 during the period of Governor-General G.A.Baron Van Der Capellen and activities in the island were normal again in 1848. In 1856 a floating shipyard was built. However, the construction of Tanjung Priok harbour in 1883 resulted in a decline in the role and significance of Onrust island.

In 1911–1933, Onrust island became a quarantine station for pilgrims returning from the Hajj. A barrack was built in 1911 that contained 35 units for about 100 pilgrims. From 1933 until 1940, the Dutch used Onrust to hold the mutineers involved in the Incident of the Seven Provinces (Zeven Provincien). In 1940, the Dutch used it to hold Germans, such as Steinfurt, who was the Chief Administrator of Onrust Island. After the Japanese invaded Indonesia in 1942, the role of Onrust island declined again and it became a prison for serious criminals.

After Indonesia proclaimed independence in 1945, the island became a leprosarium under the control of the Indonesia Ministry of Health, until 1960. The leprosarium then relocated to Post VII at Tanjung Priok Port.